Uncaria-Mitragyna Alkaloids

Uncaria gambier (Rubiaceae), a woody climber with recurved hooks, grows wild in eastern India, Malaysia, and Sumatra and is also cultivated in the Malaysian 

Three alkaloids, gambirtannine, dihydrogambirtannine, and oxogambirtan-nine, have been isolated from gambir (110). These alkaloids are considered to be generated from yohimbine-type alkaloids by dehydration and aromatization. 

Uncaria rhynchophylla is a climbing vine tree growing in China, Japan, and other temperate Asian countries. Directly above its leaves are hooks into which small stems metamorphose. 

Indole alkaloids hirsutine and hirsuteine are the major constituents of the root bark of Uncaria rhynchophylla. Along with these, minor indole alkaloids cor- 

Liquid chromatographic studies have further confirmed these differences in alkaloidal constituents of each part of this plant (165). 

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The monoterpenoid indole alkaloids constitute a laige group and careful investigation of plants, particularly from the Apocynaceae (Kopsia, Tabernaemontana, Alstonia, Leuconotis) and Rubiaceae (Uncaria, Mitragyna) have yielded many novel compounds. 

Epiallo Series. Previously, only speciociliatine (63) was known as a cory-nantheine-type alkaloid having an epiallo skeleton. Two new alkaloids in this series were isolated during the last decade, i.e., epiallocorynantheine (64) from Uncaria attenuata (59) and 3-isocorynantheidine (65) from Mitragyna speciosa Korth. (58). 

Glycosidic indole alkaloids have also been isolated cadambine from the bark of Adina cordifolia Hook. f. (94) and 3a-dihydrocadambine from leaves of Anthocephalus chinensis (Lamk.) A. Rich ex Walp. (95). The /3-carboline alkaloid harman is found in the leaves of both Mitragyna hirsuta (64) and Uncaria canescens Korth. (96). 

Chemistry of indole alkaloids related to the corynanthe-type from Uncaria, Nauclea, and Mitragyna plants 05COC1445. 

Hirsutfaife). A name used for four different compounds a) l-isothiocyanato-8-(methylsulfinyl)oc-tane, see mustard oils. - b) A corynantheine alkaloid fmm Mitragyna and Uncaria species, C22H28N2O3, Mr 368.48, cryst., mp. 101 °C, [aJu +68.6° (CHCI3). The... 

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